Racemising 1-phenyl-2-aminopropanes - by oxidising to ketone with N-chloro succinimide then reaction with amine

摘要

Racemic cpds. of formula (I) Z = CF3O, CF3S, CF3,Cl or H, R1 and R2 are same or different H, 1-5C alkyl, 3-6C cycloalkyl, opt. chlorinated phenylalkyl or NR1-R2 is a heterocycle) is prepd. by (a) oxidising a particular optical antipode of (I) to ketone (II) by reaction with N-chlorosuccinimide at reflux in a polar solvent, treatment with alkali alkoxide then acidification, and (b) conversion of (II) to racemic (I) by reaction with HNR1R2. Process allows unwanted isomer of (I) to be racemised and hence increases yield of the desired isomer.